An accident dosimeter.
The Escaflowne limited edition DVD set with Black Escaflowne figurine
I own
a binary clock, my grandfather’s slide rule, and I just received as a wedding shower gift (after much pleading to my mom and sister) these appetizer dishes
The badassest by far. I have mine displayed on a shelf shared with a the few Alternators that caught my fancy and some of wife’s collector Barbie dolls. OP is da mac(truck)daddy! 
I had almost forgot the 4th contender:
-His & hers Serentiy Halloween costumes worn to an Alamo Drafthouse costume contest & screening.
As for my wife, I am by far her nerdiest posession.
I have a framed set of the 4 TV Guides with Star Trek captains on the cover. (It was a gift!)
I own several Star Trek Christmas ornamanents. My favorite is the shuttlecraft, which says “Spock to Enterprise. Happy Holidays. Live Long and Prosper.” when you push a button.
I have a Blue Sun T-shirt, and I have Buffy: The Chosen Collection DVD set.
You guys are such dweebs.
Hmmm… where do I begin? My 400 + horse figurines? My LOTR figurine collection, which includes a Legolas Ken doll, and a life-size cardboard Legolas standee? My really putzy CD collection, which includes the Osmond Brothers, the Partridge family, and most recently, Ace Young & Bucky Covington?
I think I win.
I’m not sure which of my possessions are the nerdiest.
Is it my Mace Windu Light Saber?
Or my full size, framed attraction poster of the Skyway from Disneyland?
My Headless Horseman, Ichobod Crane figures from the Sleepy Hollow movie?
My framed photo of myself, standing, well, digitally inserted, with Kirk, Spock and McCoy in Star Trek II?
Or perhaps it is just my soul.
Either my Dr. Phibes action figure, or the Ring of Power in it’s velvet-covered holder under a bell jar.
Or maybe the “Aliens” Colonial Marines tech manual, with all the pencil markings from where I made measurments from the diagrams.
Many, many things, but the most visible is one of these which I wear on a chain around my neck. I’ve yet to meet anyone who’s actually recognized it, which is doubly depressing in that I work at a video game company. Goddamned geeks got no sense of history, any more.
(Here’s the reverse, for those what care about such things.)
I have some little-used somewhat obscure roleplaying books. Rules for GURPS AutoDuel, Teenage Mutant Ninja Turtles, Top Secret, Star Wars, and the second edition of Paranoia. I also have a Star Wars Sourcebook and some extra Paranoia rules. The reason I have these is that at one time I had plans to set up a RPG-centric BBS.
I also have a card game that’s like a combination of Car Wars and Mille Bornes.
I can say I recognise it, and am envious of it at the same time.
A Mickey Mouse rear view moniter mirror.
A Crayola Crayon collection that has over 400 uniquely named crayons.
A 148 and growing Monopoly token collection.
(bolding mine)
My daughter has one of those! She loves to leave it standing in dark corners when guests come over. Legsy has scared the crap out of several of my friends. We also pull him out of her room and decorate him on holidays. He’s worn bunny ears, Christmas ornaments as earrings, and stood next to a stuffed turkey with an arrow through it.
lisacurl, guilty as charged. I’m **wisdomy ** at OTZ.
A slide rule
Bow before me!
We have the compact O.E.D. and we use it all the time to settle marital arguments, e.g. “See! I told you that decimate means to reduce by one tenth!”.
Finding Serenity, a book about Firefly.
The Grinch Who Stole Christmas in Latin.
Hmm. Now that I think about it, we’ve got lots of weird stuff, but not that much nerdy stuff. Unless you count about two thousand books.
Like has been said before, depends on the discipline:
1.* OS/2 Warp, 3.5" Floppy edition
2. *WANG 32 mb Disk Pack
3. *not one, but two 700r4 Reaction Shells broken in the exact same way. They make a nice set of bookends and ring like a well struck bell when hit by
4. *two titanium Ford Racing valves…which are good to show the difference between a worn out valve and one that still has the three angle grind.
5. An LS-1 Corvette beauty cover signed by 6 people instrumental in creating the C5 Corvette
6. A kit that’ll pull any power steering pump pulley from Chevy or Chrysler products.
7. Gaston - a Gargoyle. He’s decorated year round with a trick or treat jack-o-lantern, bunny ears, and xmas wreath
8. four post Car Lift
9. *Hoberman Sphere
- = items at the Office
It’s either my Rubik’s Revenge or my trusty 10 inch sliderule (only nerdy since I’m 19 years old).
A full-size Tapper arcade game. It was my favorite when I was 14 years old, so I eventually bought one for myself. Actually, I need to sell it because I may be moving. So now I need to find another former video game nerd from my generation…
Currently, a Ward & Storey aluminum hoof protractor.
OK, so it doesn’t beep, spin or light up. It’s still nerdy.